Diagnostic MiRNA markers for Parkinson&#39;s disease

ABSTRACT

The invention relates to methods for diagnosing Parkinson&#39;s Disease PAD) with miRNA markers. Towards the identification of biomarkers for diagnosis of PD, a comprehensive analysis of miRNA expression patterns was obtained. Significantly deregulated miRNAs were identified.

PRIORITY STATEMENT

This application is a national phase application under 35 U.S.C. § 371 of PCT International Application No. PCT/EP2013/065819 which has an International filing date of 26 Jul. 2013, which designated the United States of American, and which claims priority to European patent application number 12192974.9 filed 16 Nov. 2012. The entire contents of each patent application referenced above are hereby incorporated by reference.

REFERENCE TO A SEQUENCE LISTING

This application contains references to amino acid sequences and/or nucleic acid sequences 15 which have been submitted concurrently herewith as the sequence listing text file 61494540_1.TXT file size 33.9 KiloBytes (KB), created on 5 Aug. 2013. The aforementioned sequence listing is hereby incorporated by reference in its entirety pursuant to 37 C.F.R. § 1.52 (e)(5).

FIELD OF THE INVENTION

The invention relates to novel markers for Parkinson's disease (PD).

BACKGROUND OF THE INVENTION

Very recently, molecular diagnostics has increasingly gained in importance. It has found an entry into the clinical diagnosis of diseases (inter alia detection of infectious pathogens, detection of mutations of the genome, detection of diseased cells and identification of risk factors for predisposition to a disease).

In particular, through the determination of gene expression in tissues, nucleic acid analysis opens up very promising new possibilities in the study and diagnosis of disease.

Nucleic acids of interest to be detected include genomic DNA, expressed mRNA and other RNAs such as MicroRNAs (abbreviated miRNAs). MiRNAs are a new class of small RNAs with various biological functions (A. Keller et al., Nat Methods. 2011 8(10):841-3). They are short (average of 20-24 nucleotide) ribonucleic acid (RNA) molecules found in eukaryotic cells. Several hundred different species of microRNAs (i.e. several hundred different sequences) have been identified in mammals. They are important for posttranscriptional gene-regulation and bind to complementary sequences on target messenger RNA transcripts (mRNAs), which can lead to translational repression or target degradation and gene silencing. As such they can also be used as biologic markers for research, diagnosis and therapy purposes.

Parkinson's disease (P) is a degenerative disorder of the central nervous system. The motor symptoms of Parkinson's disease result from the death of dopamine-generating cells in the nervous system; the cause of this cell death is unknown.

Early symptoms are often mistaken to be age-related problems. Parkinson's disease affects movement, producing motor symptoms and may cause mood, cognition, behavior or thought alterations. Diagnosis of Parkinson's disease is based on the medical history and a neurological examination. There is no lab test that will clearly identify the disease, but imaging modalities are sometimes used to rule out other disorders.

Symptoms, such as frailty and motor symptoms can be similar to other neurological disorders. Diagnosis can be time consuming, expensive and difficult. In particular, the reliable and early diagnosis of Parkinson based on non-invasive molecular biomarkers remains a challenge.

Therefore, there exists an unmet need for an efficient, simple, reliable diagnostic test for PD.

OBJECT OF THE INVENTION

The technical problem underlying the present invention is to provide biological markers allowing to diagnose, screen for or monitor Parkinson's disease, predict the risk of developing Parkinson's disease, or predict an outcome of Parkinson's disease.

SUMMARY OF THE INVENTION

Before the invention is described in detail, it is to be understood that this invention is not limited to the particular component parts of the process steps of the methods described as such methods may vary. It is also to be understood that the terminology used herein is for purposes of describing particular embodiments only, and is not intended to be limiting. It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include singular and/or plural referents unless the context clearly dictates otherwise. It is also to be understood that plural forms include singular and/or plural referents unless the context clearly dictates otherwise. It is moreover to be understood that, in case parameter ranges are given which are delimited by numeric values, the ranges are deemed to include these limitation values.

In its most general terms, the invention relates to a collection of miRNA markers useful for the diagnosis, prognosis and prediction of Parkinson's Disease.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the distribution of novel nucleic acid molecule miRNA markers (a) of the invention vs. known miRNA markers (b) in blood;

FIG. 2 shows delta CT values of a first exemplary novel nucleic acid molecule miRNA marker of the invention, brain-mir-112, in samples of patients having different neuronal disorders and controls;

FIG. 3 shows delta CT values of a further exemplary novel nucleic acid molecule miRNA marker of the invention, brain-mir-161 in different samples of patients having different neuronal disorders and controls;

FIG. 4 shows delta CT values of six miRNA markers in different samples of patients having Parkinsons's disease, different neuronal disorders (ND) and healthy controls;

FIG. 5 shows t-test values of of six miRNA markers in different samples of patients having Parkinsons's disease vs different neuronal disorders (ND) and healthy controls;

FIG. 6 shows the validation of 12 miRNAs in 7 diseases (AD, MCI, PD, DEP, CIS, SCH, and BD and controls). The 12 miRNAs are (denoted by columns 1-12, respectively) hsa-let-7f-5p, hsa-miR-1285-5p, hsa-miR-107, hsa-miR-103a-3p, hsa-miR-26b-3p, hsa-miR-26a-5p, hsa-miR-532-5p, hsa-miR-151a-3p, brain-mir-161, hsa-let-7d-3p, brain-mir-112, and hsa-miR-5010-3p;

FIG. 7 shows the combined score of the 7-miRNA signature brain-mir-112, hsa-miR-5010-3p, hsa-miR-103a-3p, hsa-miR-107, hsa-let-7d-3p, hsa-miR-532-5p, and brain-mir-161 for all diseases. The combined score (y-axis) was obtained using quantitative RT PCR; and

FIG. 8 shows the combined score of the 12-miRNA signature hsa-let-7f-5p, hsa-miR-1285-5p, hsa-miR-107, hsa-miR-103a-3p, hsa-miR-26b-3p, hsa-miR-26a-5p, hsa-miR-532-5p, hsa-miR-151a-3p, brain-mir-161, hsa-let-7d-3p, brain-mir-112, and hsa-miR-5010-3p for all diseases. The combined score (y-axis) was obtained using quantitative RT PCR.

DETAILED DESCRIPTION OF THE INVENTION Definitions

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The term “predicting an outcome” of a disease, as used herein, is meant to include both a prediction of an outcome of a patient undergoing a given therapy and a prognosis of a patient who is not treated.

An “outcome” within the meaning of the present invention is a defined condition attained in the course of the disease. This disease outcome may e.g. be a clinical condition such as “relapse of disease”, “remission of disease”, “response to therapy”, a disease stage or grade or the like.

A “risk” is understood to be a probability of a subject or a patient to develop or arrive at a certain disease outcome. The term “risk” in the context of the present invention is not meant to carry any positive or negative connotation with regard to a patient's wellbeing but merely refers to a probability or likelihood of an occurrence or development of a given event or condition.

The term “clinical data” relates to the entirety of available data and information concerning the health status of a patient including, but not limited to, age, sex, weight, menopausal/hormonal status, etiopathology data, anamnesis data, data obtained by in vitro diagnostic methods such as blood or urine tests, data obtained by imaging methods, such as x-ray, computed tomography, MRI, PET, spect, ultrasound, electrophysiological data, genetic analysis, gene expression analysis, biopsy evaluation, intraoperative findings.

The term “classification of a sample” of a patient, as used herein, relates to the association of said sample with at least one of at least two categories. These categories may be for example “high risk” and “low risk”; or high, intermediate and low risk; wherein risk is the probability of a certain event occurring in a certain time period, e.g. occurrence of disease, progression of disease, etc. It can further mean a category of favourable or unfavourable clinical outcome of disease, responsiveness or non-responsiveness to a given treatment or the like. Classification may be performed by use of an algorithm, in particular a discrimant function. A simple example of an algorithm is classification according to a first quantitative parameter, e.g. expression level of a nucleic acid of interest, being above or below a certain threshold value. Classification of a sample of a patient may be used to predict an outcome of disease or the risk of developing a disease. Instead of using the expression level of a single nucleic acid of interest, a combined score of several nucleic acids of interest of interest may be used. Further, additional data may be used in combination with the first quantitative parameter. Such additional data may be clinical data from the patient, such as sex, age, weight of the patient, disease grading etc.

A “discriminant function” is a function of a set of variables used to classify an object or event. A discriminant function thus allows classification of a patient, sample or event into a category or a plurality of categories according to data or parameters available from said patient, sample or event. Such classification is a standard instrument of statistical analysis well known to the skilled person. E.g. a patient may be classified as “high risk” or “low risk”, “in need of treatment” or “not in need of treatment” or other categories according to data obtained from said patient, sample or event. Classification is not limited to “high vs. low”, but may be performed into a plurality of categories, grading or the like. Examples for discriminant functions which allow a classification include, but are not limited to discriminant functions defined by support vector machines (SVM), k-nearest neighbors (kNN), (naive) Bayes models, or piecewise defined functions such as, for example, in subgroup discovery, in decision trees, in logical analysis of data (LAD) an the like.

The term “expression level” refers, e.g., to a determined level of expression of a nucleic acid of interest. The term “pattern of expression levels” refers to a determined level of expression com-pared either to a reference nucleic acid, e.g. from a control, or to a computed average expression value, e.g. in DNA-chip analyses. A pattern is not limited to the comparison of two genes but is also related to multiple comparisons of genes to reference genes or samples. A certain “pattern of expression levels” may also result and be determined by comparison and measurement of several nucleic acids of interest disclosed hereafter and display the relative abundance of these transcripts to each other. Expression levels may also be assessed relative to expression in different tissues, patients versus healthy controls, etc.

A “reference pattern of expression levels”, within the meaning of the invention shall be understood as being any pattern of expression levels that can be used for the comparison to another pattern of expression levels. In a preferred embodiment of the invention, a reference pattern of expression levels is, e.g., an average pattern of expression levels observed in a group of healthy or diseased individuals, serving as a reference group.

In the context of the present invention a “sample” or a “biological sample” is a sample which is derived from or has been in contact with a biological organism. Examples for biological samples are: cells, tissue, body fluids, biopsy specimens, blood, urine, saliva, sputum, plasma, serum, cell culture supernatant, and others.

A “probe” is a molecule or substance capable of specifically binding or interacting with a specific biological molecule. The term “primer”, “primer pair” or “probe”, shall have ordinary meaning of these terms which is known to the person skilled in the art of molecular biology. In a preferred embodiment of the invention “primer”, “primer pair” and “probes” refer to oligonucleotide or polynucleotide molecules with a sequence identical to, complementary too, homologues of, or homologous to regions of the target molecule or target sequence which is to be detected or quantified, such that the primer, primer pair or probe can specifically bind to the target molecule, e.g. target nucleic acid, RNA, DNA, cDNA, gene, transcript, peptide, polypeptide, or protein to be detected or quantified. As understood herein, a primer may in itself function as a probe. A “probe” as understood herein may also comprise e.g. a combination of primer pair and internal labeled probe, as is common in many commercially available qPCR methods.

A “gene” is a set of segments of nucleic acid that contains the information necessary to produce a functional RNA product in a controlled manner. A “gene product” is a biological molecule produced through transcription or expression of a gene, e.g. an mRNA or the translated protein.

A “miRNA” is a short, naturally occurring RNA molecule and shall have the ordinary meaning understood by a person skilled in the art. A “molecule derived from a miRNA” is a molecule which is chemically or enzymatically obtained from an miRNA template, such as cDNA.

The term “array” refers to an arrangement of addressable locations on a device, e.g. a chip device. The number of locations can range from several to at least hundreds or thousands.

Each location represents an independent reaction site. Arrays include, but are not limited to nucleic acid arrays, protein arrays and antibody-arrays. A “nucleic acid array” refers to an array containing nucleic acid probes, such as oligonucleotides, polynucleotides or larger portions of genes. The nucleic acid on the array is preferably single stranded. A “microarray” refers to a biochip or biological chip, i.e. an array of regions having a density of discrete regions with immobilized probes of at least about 100/cm2.

A “PCR-based method” refers to methods comprising a polymerase chain reaction PCR. This is a method of exponentially amplifying nucleic acids, e.g. DNA or RNA by enzymatic replication in vitro using one, two or more primers. For RNA amplification, a reverse transcription may be used as a first step. PCR-based methods comprise kinetic or quantitative PCR (qPCR) which is particularly suited for the analysis of expression levels,). When it comes to the determination of expression levels, a PCR based method may for example be used to detect the presence of a given mRNA by (1) reverse transcription of the complete mRNA pool (the so called transcriptome) into cDNA with help of a reverse transcriptase enzyme, and (2) detecting the presence of a given cDNA with help of respective primers. This approach is commonly known as reverse transcriptase PCR (rtPCR). The term “PCR based method” comprises both end-point PCR applications as well as kinetic/real time PCR techniques applying special fluorophors or intercalating dyes which emit fluorescent signals as a function of amplified target and allow monitoring and quantification of the target. Quantification methods could be either absolute by external standard curves or relative to a comparative internal standard.

The term “next generation sequencing” or “high throughput sequencing” refers to high-throughput sequencing technologies that parallelize the sequencing process, producing thousands or millions of sequences at once. Examples include Massively Parallel Signature Sequencing (MPSS) Polony sequencing, 454 pyrosequencing, Illumina (Solexa) sequencing, SOLiD sequencing, Ion semiconductor sequencing, DNA nanoball sequencing, Helioscope™ single molecule sequencing, Single Molecule SMRT™ sequencing, Single Molecule real time (RNAP) sequencing, Nanopore DNA sequencing.

The term “marker” or “biomarker” refers to a biological molecule, e.g., a nucleic acid, peptide, protein, hormone, etc., whose presence or concentration can be detected and correlated with a known condition, such as a disease state, or with a clinical outcome, such as response to a treatment.

In particular, the invention relates to a method of classifying a sample of a patient suffering from or at risk of developing Parkinson's Disease, wherein said sample is a blood sample, said method comprising the steps of:

a) determining in said sample an expression level of at least one miRNA selected from the group consisting of miRNAs having the sequence SEQ ID NO 69, SEQ ID NO 142, SEQ ID NO 2, SEQ ID NO 59, SEQ ID NO 58 and SEQ ID NO 65;

b) comparing the pattern of expression level(s) determined in step a) with one or several reference pattern(s) of expression levels; and

c) classifying the sample of said patient from the outcome of the comparison in step b) into one of at least two classes.

These sequences correspond to the following miRNAs: miR-1285-5p (SEQ ID NO: 69), miR-151-3p (SEQ ID NO: 58), hsa-let-7f (SEQ ID NO: 2) and miR-5010 (SEQ ID NO: 65) and newly discovered miRNAs, namely brain-mir-112 (SEQ ID NO: 59) and brain-mir-161 (SEQ ID NO: 142),

A reference pattern of expression levels may, for example, be obtained by determining in at least one healthy subject the expression level of at least one miRNA selected from the group consisting of miRNAs having the sequence SEQ ID NO 69, SEQ ID NO 142, SEQ ID NO 2, SEQ ID NO 59, SEQ ID NO 58 and SEQ ID NO 65.

A reference pattern of expression levels may, for example, further be obtained by determining in at least one patient having another neurological disease the expression level of at least one miRNA selected from the group consisting of miRNAs having the sequence SEQ ID NO 69, SEQ ID NO 142, SEQ ID NO 2, SEQ ID NO 59, SEQ ID NO 58 and SEQ ID NO 65. Examples for other neurological disease include Alzheimer's Disease (AD) Cognitive Impairment (MCI), Multiple Sclerosis (herein also referred to as Clinically Isolated Syndrome, CIS), Mild Depression (n=15), Bipolar Disorder (BD), and Schizophrenia (Schiz).

It is within the scope of the invention to assign a numerical value to an expression level of the at least one miRNA determined in step a).

It is further within the scope of the invention to mathematically combine expression level values to obtain a pattern of expression levels in step (b), e.g. by applying an algorithm to obtain a normalized expression level relative to a reference pattern of expression level(s).

In a further aspect the invention relates to a method for diagnosing Parkinson's Disease, predicting risk of developing Parkinson's Disease, or predicting an outcome of Parkinson's Disease in a patient suffering from or at risk of developing Parkinson's Disease, said method comprising the steps of:

a) determining in a blood sample from said patient, the expression level of at least one miRNA selected from the group consisting of miRNAs with the sequence SEQ ID NO 69, SEQ ID NO 142, SEQ ID NO 2, SEQ ID NO 59, SEQ ID NO 58 and SEQ ID NO 65;

b) comparing the pattern of expression level(s) determined in step a) with one or several reference pattern(s) of expression levels; and

c) diagnosing Parkinson's Disease, predicting a risk of developing Parkinson's Disease, or predicting an outcome of Parkinson's Disease from the outcome of the comparison in step b).

According to an aspect of the invention, said at least one miRNA is selected from the group consisting of miRNAs with the sequence SEQ ID NO 69, SEQ ID NO 142, SEQ ID NO 2, SEQ ID NO 59, SEQ ID NO 58 and SEQ ID NO 65.

According to an aspect of the invention, the expression levels of a plurality of miRNAs are determined as expression level values and step (b) comprises mathematically combining the expression level values of said plurality of miRNAs.

It is within the scope of the invention to apply an algorithm to the numerical value of the expression level of the at least one miRNA determined in step a) to obtain a disease score to allow classification of the sample or diagnosis, prognosis or prediction of the risk of developing Parkinson's Disease, or prediction of an outcome of Parkinson's Disease. A non-limiting example of such an algorithm is to compare the numerical value of the expression level against a threshold value in order to classify the result into one of two categories, such as high risk/low risk, diseased/healthy or the like. A further non-limiting example of such an algorithm is to combine a plurality of numerical values of expression levels, e.g. by summation, to obtain a combined score. Individual summands may be normalized or weighted by multiplication with factors or numerical values representing the expression level of a miRNA, numerical values representing clinical data, or other factors.

It is within the scope of the invention to apply a discriminant function to classify a result, diagnose disease, predict an outcome or a risk.

According to an aspect of the invention, the expression level in step (a) is obtained by use of a method selected from the group consisting of a sequencing-based method, an array based method and a PCR based method.

According to an aspect of the invention, the expression levels of at least 2, 3, 4, 5, or 6, miRNAs are determined to obtain a pattern of expression levels.

The invention further relates to a kit for performing the methods of the invention, said kit comprising

means for determining in said blood sample from said patient, an expression level of at least one miRNA selected from the group consisting of miRNAs with the sequence SEQ ID NO 69, SEQ ID NO 142, SEQ ID NO 2, SEQ ID NO 59, SEQ ID NO 58 and SEQ ID NO 65.

The means for determining the expression level of said at least one miRNA may comprise an oligonucleotide probe for detecting or amplifying said at least one miRNA, means for determining the expression level based on an array-based method, a PCR based method, a sequencing based method or any other suitable means for determining the expression level.

According to an aspect of the invention, the kit further comprises at least one reference pattern of expression levels for comparing with the expression level of the at least one miRNA from said sample. The reference pattern of expression may include at least one digital or numerical information and may be provided in any readable or electronically readable form, including, but not limited to printed form, electronically stored form on a computer readable medium, such as CD, smart card, or provided in downloadable form, e.g. in a computer network such as the internet.

The invention further relates to computer program product useful for performing the methods of the invention, comprising

-   -   means for receiving data representing an expression level of at         least one miRNA in a patient blood sample selected from the         group consisting of miRNAs with the sequence SEQ ID NO 69, SEQ         ID NO 142, SEQ ID NO 2, SEQ ID NO 59, SEQ ID NO 58 and SEQ ID NO         65,     -   means for receiving data representing at least one reference         pattern of expression levels for comparing with the expression         level of the at least one miRNA from said sample,     -   means for comparing said data representing the expression level         of the at least one miRNA in a patient sample, and     -   optionally means for determining a diagnosis of Parkinson's         Disease, a prediction of a risk of developing Parkinson's         Disease, or a prediction of an outcome of Parkinson's Disease         from the outcome of the comparison in step b).

The computer program product may be provided on a storable electronic medium, such as a solid state memory, disk, CD or other. It may be stored locally on a computer. It may be implemented as network-based program or application, including a web- or internet-based application. It may be implemented in a diagnostic device, such as an analyzer instrument.

It may be operably connected to a device for outputting information, such as a display, printer or the like.

EXAMPLES

Additional details, features, characteristics and advantages of the object of the invention are further disclosed in the following description and figures of the respective examples, which, in an exemplary fashion, show preferred embodiments of the present invention. However, these examples should by no means be understood as to limit the scope of the invention.

The invention relates to methods for diagnosing Parkinson's Disease with miRNA markers.

Diagnosis of Parkinson's Disease can be challenging in patients presenting with generally age-related syndromes such as frailty. In particular, it is difficult to diagnose the earliest stages of disease. However, it would be particularly desirable to have a reliable diagnostic test for this stage of disease, as the chance of therapeutic and social intervention is improved during this early disease stage.

Here, the abundance of miRNAs in blood samples of Parkinson's Disease patients has been compared in an unbiased approach against healthy controls and patients suffering from other neuronal disorders. This approach involved a massive effort of sequencing miRNAs from samples and thus was open to the discovery of novel markers not yet described in the prior art. Further, the use of blood samples as a source of expression information of miRNA markers has several tangible advances which are not available in other sample sources such as serum or tissue, such as ease of sample procurement and handling, sample preparation, and robustness and consistency of expression patterns.

Materials and Methods

Patient Cohorts

The expression of miRNAs in peripheral blood of a total of 219 patients and healthy controls was determined, either by NGS or by qRT-PCR or both. Blood was obtained from patients with Parkinson's Disease (PD) (n=9), patients with Alzheimer's Disease (AD) (n=106), patients with Mild Cognitive Impairement (MCI) (n=21), patients with Multiple Sclerosis (Clinically Isolated Syndrome, CIS) (n=17), patients with Mild Depression (DEP) (n=15), Bipolar Disorder (BD) (n=15), Schizophrenia (Schiz) (n=14), and from healthy controls (n=22).

First, samples from AD patients (n=48), MCI patients (n=20) and healthy controls (n=22) were analyzed by Next-generation sequencing. For validation purposes the expression of single miRNAs was analyzed using qRT-PCR in the same samples as used for NGS, if enough RNA was available. The number of samples was further expanded by further samples from patients with AD, CIS, PD, DEP, BD, and Schiz, resulting in a total of 205 samples analyzed by qRT-PCR. In detail, a total of 95 samples from AD patients, 19 samples from MCI patients, 17 samples from CIS patients, 9 samples from PD patients, 15 samples from DEP patients, 15 samples from BD patients, 14 samples from Schiz patients, and 21 samples from healthy controls were analyzed.

RNA Isolation

Total RNA including miRNA was isolated using the PAXgene Blood miRNA Kit (Qiagen) following the manufacturer's recommendations. Isolated RNA was stored at −80° C. RNA integrity was analyzed using Bioanalyzer 2100 (Agilent) and concentration and purity were measured using NanoDrop 2000 (Thermo Scientific). A total of four samples (three controls and one RRMS) failed the quality criteria and were excluded from the study.

Library Preparation and Next-Generation Sequencing

For the library preparation, 200 ng of total RNA was used per sample, as determined with a RNA 6000 Nano Chip on the Bioanalyzer 2100 (Agilent). Preparation was performed following the protocol of the TruSeq Small RNA Sample Prep Kit (Illumina). Concentration of the ready prepped libraries was measured on the Bioanalyzer using the DNA 1000 Chip. Libraries were then pooled in batches of six samples in equal amounts and clustered with a concentration of 9 pmol in one lane each of a single read flowcell using the cBot (Illumina). Sequencing of 50 cycles was performed on a HiSeq 2000 (Illumina). Demultiplexing of the raw sequencing data and generation of the fastq files was done using CASAVA v.1.8.2.

NGS Data Analysis

The raw illumina reads were first preprocessed by cutting the 3′ adapter sequence using the programm fastx_clipper from the FASTX-Toolkit (Website: hannonlab.cshl/fastx_toolkit). Reads shorter than 18 nts after clipping were removed. The remaining reads are reduced to unique reads and their frequency per sample to make the mapping steps more time efficient. For the remaining steps, we used the miRDeep2 pipeline. These steps consist of mapping the reads against the genome (hg19), mapping the reads against miRNA precursor sequences from mirbase release v18, summarizing the counts for the samples, and the prediction of novel miRNAs. Since the miRDeep2 pipeline predicts novel miRNAs per sample, the miRNAs were merged afterwards as follows: first, the novel miRNAs per sample that have a signal-to-noise ratio of more than 10 were extracted. Subsequently, only those novel miRNAs that are located on the same chromosome were merged, and both their mature forms share an overlap of at least 11 nucleotides.

In particular, six miRNA markers were selected for their ability to differentiate between PD and (healthy) controls as well as PD and other neurological diseases. Out of the NGS results these six miRNAs were selected, since they were deregulated in both the comparison between patients with Parkinson's Disease and patients with other neurological disease, and the comparison between patients with Parkinson's Disease and healthy individuals. Four of the six miRNAs, namely miR-1285-5p (SEQ ID NO: 69), miR-151-3p (SEQ ID NO: 58), hsa-let-7f (SEQ ID NO: 2) and miR-5010 (SEQ ID NO: 65) were already known mature miRNAs included in miRBase, two miRNAs, namely brain-mir-112 (SEQ ID NO: 59) and brain-mir-161 (SEQ ID NO: 142), were newly identified and not yet included in miRBase.

The miScript PCR System (Qiagen) was used for reverse transcription and qRT-PCR. A total of 200 ng RNA was converted into cDNA using the miScript Reverse Transcription Kit according to the manufacturers' protocol. For each RNA we additionally prepared 5 μl reactions containing 200 ng RNA and 4 μl of the 5× miScript RT Buffer but no miScript Reverse Transcriptase Mix, as negative control for the reverse transcription (RT-control). The qRT-PCR was performed with the miScript SYBR® Green PCR Kit in a total volume of 20 μl per reaction containing 1 μl cDNA according to the manufacturers' protocol. For each miScript Primer Assay we additionally prepared a PCR negative-control with water instead of cDNA (non-template control, NTC).

Bioinformatics Analysis

First the read counts were normalized using standard quantile normalization. All miRNAs with less than 50 read counts were excluded from further considerations. Next, we calculated for each miRNA the area under the receiver operator characteristic curve (AUC), the fold-change, and the significance value (p-value) using t-tests. All significance values were adjusted for multiple testing using the Benjamini Hochberg approach. The bioinformatics analyses have been carried out using the freely available tool. Furthermore, we carried out a miRNA enrichment analysis using the TAM tool (Website: 202.38.126.151/hmdd/tools/tam.html).

Computing Combined Scores

Briefly, to compute a combined expression score for n up-regulated markers and m downregulated markers the difference d between the expression value x_((a)) of a patient a and the average expression value of all controls μ is determined. For down-regulated markers, the difference can be multiplied by (−1), thus yielding a positive value. The differences for n markers can be added up to yield a combined score Z, such that Z _((a)) =Σd _((1-n))(upregulated)+Σ(−1)d _((1-m))(down-regulated) Wherein d=x _((a))−μ

To make combined scores between different marker scores comparable (e.g. to compare a (n+m)=7 marker score against a (n+m)=12 marker score, the combined score can be divided by (n+m): Zcomp=1/(n+m)(Σd _((1-n))(upregulated)+Σ(−1)d _((1-m))(down-regulated))

Other factors can be applied to the individual summands d of the combined score or the combined score Z as a whole.

Results

The most abundant miRNAs were hsa-miR-486-5p with an average read-count of 13,886,676 and a total of 1.2 billion reads mapping to this miRNA, hsa-miR-92a-3p with an average of 575,359 reads and a total of 52 million reads mapping to this miRNA and miR-451a with an average of 135,012 reads and a total of 12 million reads mapping to this miRNA.

The invention provides very rare variants of miRNAs that are present in blood cells. While common variants have already been discovered and are heavily overlapping with miRNAs discovered from tissue biopsies, a substantial part of miRNAs is expected to be still unknown. Herein, patients suffering neurological disorders including mild cognitive impairment, Alzheimers disease or multiple sclerosis as well as unaffected controls were characterized.

About 2 billion sequences from the patient and control samples were generated, of which around 1.4 billion matched to known or predicted novel miRNAs. As detailed in FIG. 1, the vast majority of these sequences matched known miRNAs (99.9%) while only around 0.1% matched to predicted novel miRNAs, pointing out why the enormous sequencing capacity had to be used. It has been found that these novel miRNAs can be used as diagnostic markers indicative of disease conditions such as neuronal diseases, e.g. Parkinsons's Disease.

These miRNA candidates have generally however been much less abundant as compared to the known human miRNAs.

In FIG. 2 and FIG. 3 the delta CT values of a first exemplary novel nucleic acid molecule miRNA marker of the invention, brain-mir-112, and of a further exemplary novel nucleic acid molecule miRNA marker of the invention, brain-mir-161, in samples of patients having different Neurological diseases AD (two cohorts), BD, CIS, DEP, MCI, and Schiz (col. 1, 3-8) and controls (col. 2).

A list of all miRNA molecules described herein is given in Supplemental Table 2 containing an overview of the miRNA markers, including sequence information.

It is noted that the mature miRNa originate from miRNA precursor molecules of length of around 120 bases. Several examples exists where the miRNA precursors vary from each other while the subset of the around 20 bases belonging to the

mature miRNA are identical. Thus, novel mature miRNAs can have the same sequence but different SEQ ID NO identifiers.

MiRNA markers are denoted by their common name (e.g. has-miR-144-5p or hsa-let 7f-5p) and are searchable in publically available databases. In this invention there are also described novel miRNA markers which have been named with names beginning with the prefix “brain-miR”. They are listed in supplemental table 1 with their sequence and their SEQ ID NO according to the sequence protocol.

Besides single markers, combinations of multiple markers have demonstrated a potential to improve the diagnostic accuracy. We selected a signature of just 6 markers, known markers Four of the six miRNAs, namely miR-1285-5p (SEQ ID NO: 69), miR-151-3p (SEQ ID NO: 58), hsa-let-7f (SEQ ID NO: 2) and miR-5010 (SEQ ID NO: 65) and new markers brain-mir-112 (SEQ ID NO: 59) and brain-mir-161 (SEQ ID NO: 142). To combine the values of the 6 miRNAs in one score can be calculated the average z-score as detailed in the Material & Methods section. A combination of the six markers gives an improved differentiation between PD vs. controls and between PD vs. other neurological diseases.

Scores of Other Neurological Disorders

Next the question was asked whether a cohort of other neurological disorders shows likewise significant deviations to controls. We measured samples of patients with Parkinson disease, Alzheimer's disease, mild cognitive impairment, schizophrenia, bipolar disorder, multiple sclerosis (CIS) and depression patients for a signature of 7 miRNAs, namely hsa-miR-5010-3p, hsa-miR-103a-3p, hsa-miR-107, hsa-let-7d-3p, hsa-miR-532-5p, brain-mir-112 and brain-mir-161. In FIG. 6, the bar diagrams for all diseases and all miRNAs are present. Here, the Alzheimer patients score is set to 0, as described earlier we have four down- and three up-regulated miRNAs for the controls. For mild cognitive impairment patients the same four miRNAs were down- and the same three miRNAs were upregulated, providing strong evidence that the MCI signature is much closer to controls as compared to AD. For CIS patients only two miRNAs were down-regulated, while the third one was not dysregulated and the remaining three were strongly up-regulated. For Parkinson disease, the first 5 miRNAs were down—while the remaining two were strongly upregulated. For Schizophrenia and Bipolar Disease, almost all miRNAs were strongly upregulated, in contrast, for Depression all miRNAs were significantly down-regulated. In summary, the results promise that AD can not only be distinguished from controls but also very well from other neurological disorders. Of course the same z-score based approach can be applied as for the Alzheimer and control patients in order to get an overall score for each cohort.

In Tables 1 and 2, an evaluation of expression values for miR-1285-5p (SEQ ID NO: 69), miR-151-3p (SEQ ID NO: 58), hsa-let-7f (SEQ ID NO: 2), miR-5010 (SEQ ID NO: 65), brain-mir-112 (SEQ ID NO: 59), and brain-mir-161 (SEQ ID NO: 142) in PD patients, combined other neurological disease patients and healthy controls are shown.

TABLE 1 Evaluation of Expression Values for brain-mir-112 brain-mir-161 hsa-let-7f brain-mir-112 brain-mir-161 hsa-let-7f average PD 11.03491038 9.898887474 5.25843664 average ND 10.42592681 9.227711302 5.419797676 average control 11.03017957 9.726909301 4.050352325 sd PD 0.702870335 0.668545504 1.633235375 sd ND 0.740377036 1.153414403 1.965260211 sd control 0.61149943 0.653667163 1.345809868 t-test PD vs ND 0.032518756 0.017686328 0.781348899 t-test PD vs control 0.9862585 0.52560265 0.072863496

TABLE 2 Evaluation of Expression Values for miR-1285-5p miR-151-3p miR-5010-3p miR-1285-5p miR-151-3p miR-5010-3p average PD 7.652496732 5.52538961 8.591982107 average ND 7.999877681 4.975099637 8.093307165 average control 7.034357049 5.15991191 9.599724944 sd PD 0.401429288 0.776236856 0.961903123 sd ND 1.019311517 1.000358415 0.961563715 sd control 0.561150883 0.672757054 0.720844163 t-test PD vs ND 0.041164926 0.070290871 0.164327666 t-test PD vs control 0.002636065 0.240353234 0.015373015

The focused analysis of miRNAs in large cohorts and the comparison with other neurological diseases allows to improve the specificity of miRNA markers or marker combinations. This enables an identification of PD patients by in-vitro diagnostics Tracking changes in the expression pattern of markers allows to monitor progression of disease and response to therapy.

The miRNAs described herein are also potential targets for highly specific therapy of Parkinson patients.

Supplemental Table 1, Newly discovered miRNA markers SEQ ID NO miRNA Sequence 126 brain-mir-102 UAUGGAGGUCUCUGUCUGGCU 111 brain-mir-111 CACUGCUAAAUUUGGCUGGCUU  59 brain-mir-112 AGCUCUGUCUGUGUCUCUAGG  91 brain-mir-114 CACUGCAACCUCUGCCUCCGGU  97 brain-mir-12 ACUCCCACUGCUUGACUUGACUAG 160 brain-mir-129 CAUGGUCCAUUUUGCUCUGGU  54 brain-mir-145 AAGCACUGCCUUUGAACCUGA  23 brain-mir-149 AAAAGUAAUCGCACUUUUUG  41 brain-mir-150 UGAGGUAGUAGGUGGUGUGC  24 brain-mir-151 AAAAGUAAUCGCACUUUUUG 121 brain-mir-153 CCUCUUCUCAGAACACUUCCUGG 157 brain-mir-160 CACUGCAACCUCUGCCUCC 142 brain-mir-161 CUUCGAAAGCGGCUUCGGCU 116 brain-mir-166 CUGGCUGCUUCCCUUGGUCU  21 brain-mir-170 AAAAGUAAUGGCAGUUUUUG 138 brain-mir-188 CCUGACCCCCAUGUCGCCUCUGU 139 brain-mir-189 CCUGACCCCCAUGUCGCCUCUGU 137 brain-mir-190 CCUGACCCCCAUGUCGCCUCUGU 140 brain-mir-192 CCUGACCCCCAUGUCGCCUCUGU 117 brain-mir-193 AUCCCUUUAUCUGUCCUCUAGG  88 brain-mir-200 UUCCUGGCUCUCUGUUGCACA 107 brain-mir-201 CACCCCACCAGUGCAGGCUG 100 brain-mir-219 UCAAGUGUCAUCUGUCCCUAGG 124 brain-mir-220 UCCGGAUCCGGCUCCGCGCCU 146 brain-mir-23 UUAGUGGCUCCCUCUGCCUGCA  98 brain-mir-232 UUGCUCUGCUCUCCCUUGUACU  94 brain-mir-247 ACGCCCACUGCUUCACUUGAGUAG  50 brain-mir-248S GGCGGCGGAGGCGGCGGUG 113 brain-mir-251 UGGCCCAAGACCUCAGACC 169 brain-mir-258 AUCCCACCCCUGCCCCCA 110 brain-mir-279 AUCCCACCGCUGCCACAC 156 brain-mir-293 UUGGUGAGGACCCCAAGCUCGG 120 brain-mir-299 CAUGCCACUGCACUCCAGCCU  68 brain-mir-308 CACUGCACUCCAGCCUGGGUGA 141 brain-mir-311 CACUGCAACCUCUGCCUCCCGA  96 brain-mir-314 ACUCCCACUGCUUCACUUGAUUAG 150 brain-mir-319 CUGCACUCCAGCCUGGGCGA  27 brain-mir-333 AAAAGUAAUCGCAGGUUUUG 148 brain-mir-351 UGUCUUGCUCUGUUGCCCAGGU  25 brain-mir-370 GGCUGGUCUGAUGGUAGUGGGUUA  84 brain-mir-390 ACUGCAACCUCCACCUCCUGGGU 125 brain-mir-392 CCCGCCUGUCUCUCUCUUGCA  19 brain-mir-394 AAAAGUAAUCGUAGUUUUUG  67 brain-mir-395 CACUGCACUCCAGCCUGGGUGA  38 brain-mir-398 GGCUGGUCCGAGUGGAGUGGUGUU 134 brain-mir-399 CACUGCAACCUCUGCCUCC 135 brain-mir-403 AAAGACUUCCUUCUCUCGCCU 106 brain-mir-41S CCCCGCGCAGGUUCGAAUCCUG  99 brain-mir-424S CACUGCACUCCAGCCUGGGUA  73 brain-mir-431 CUCGGCCUUUGCUCGCAGCACU 103 brain-mir-52 CUGCACUCCAGCCUGGGCGAC 104 brain-mir-53 CCCAGGAGAGUUUCAGUGAUG 131 brain-mir-72S GACCACACUCCAUCCUGGGC 136 brain-mir-73 UCCGGAUGUGCUGACCCCUGCG  80 brain-mir-79 CACUGCACUCCAGCCUGGCU  81 brain-mir-80 CACUGCACUCCAGCCUGGCU  76 brain-mir-83 CAGGGUCUCGUUCUGUUGCC 112 brain-mir-88 UCUUCACCUGCCUCUGCCUGCA

Supplemental Table 2 Overview of miRNA markers, including sequence information   1 hsa-miR-144-5p GGAUAUCAUCAUAUACUGUAAG   2 hsa-let-7f-5p UGAGGUAGUAGAUUGUAUAGUU   3 hsa-let-7e-5p UGAGGUAGGAGGUUGUAUAGUU   4 hsa-let-7a-5p UGAGGUAGUAGGUUGUAUAGUU   5 hsa-miR-107 AGCAGCAUUGUACAGGGCUAUCA   6 hsa-let-7g-5p UGAGGUAGUAGUUUGUACAGUU   7 hsa-miR-103a-3p AGCAGCAUUGUACAGGGCUAUGA   8 hsa-miR-98 UGAGGUAGUAAGUUGUAUUGUU   9 hsa-miR-29c-3p UAGCACCAUUUGAAAUCGGUUA  10 hsa-miR-101-3p UACAGUACUGUGAUAACUGAA  11 hsa-miR-548h-5p AAAAGUAAUCGCGGUUUUUGUC  12 hsa-miR-106b-3p CCGCACUGUGGGUACUUGCUGC  13 hsa-miR-15a-5p UAGCAGCACAUAAUGGUUUGUG  14 hsa-miR-548g-5p UGCAAAAGUAAUUGCAGUUUUUG  15 hsa-miR-548ar- AAAAGUAAUUGCAGUUUUUGC 5p  16 hsa-miR-548x-5p UGCAAAAGUAAUUGCAGUUUUUG  17 hsa-miR-548aj- UGCAAAAGUAAUUGCAGUUUUUG   5p  18 hsa-let-7c UGAGGUAGUAGGUUGUAUGGUU  19 brain-mir-394 AAAAGUAAUCGUAGUUUUUG  20 hsa-miR-1294 UGUGAGGUUGGCAUUGUUGUCU  21 brain-mir-170 AAAAGUAAUGGCAGUUUUUG  22 hsa-miR-199a-3p ACAGUAGUCUGCACAUUGGUUA  23 brain-mir-149 AAAAGUAAUCGCACUUUUUG  24 brain-mir-151 AAAAGUAAUCGCACUUUUUG  25 brain-mir-370 GGCUGGUCUGAUGGUAGUGGGUUA  26 hsa-miR-199b-3p ACAGUAGUCUGCACAUUGGUUA  27 brain-mir-333 AAAAGUAAUCGCAGGUUUUG  28 hsa-miR-628-3p UCUAGUAAGAGUGGCAGUCGA  29 hsa-miR-190a UGAUAUGUUUGAUAUAUUAGGU  30 hsa-miR-29b-3p UAGCACCAUUUGAAAUCAGUGUU  31 hsa-miR-660-5p UACCCAUUGCAUAUCGGAGUUG  32 hsa-miR-143-3p UGAGAUGAAGCACUGUAGCUC  33 hsa-miR-548av- AAAAGUACUUGCGGAUUU 5p  34 hsa-miR-548k AAAAGUACUUGCGGAUUUUGCU  35 hsa-miR-29a-3p UAGCACCAUCUGAAAUCGGUUA  36 hsa-miR-548i AAAAGUAAUUGCGGAUUUUGCC  37 hsa-miR-17-3p ACUGCAGUGAAGGCACUUGUAG  38 brain-mir-398 GGCUGGUCCGAGUGCAGUGGUGUU  39 hsa-miR-148a-3p UCAGUGCACUACAGAACUUUGU  40 hsa-miR-126-3p UCGUACCGUGAGUAAUAAUGCG  41 brain-mir-150 UGAGGUAGUAGGUGGUGUGC  42 hsa-let-7i-5p UGAGGUAGUAGUUUGUGCUGUU  43 hsa-miR-33b-5p GUGCAUUGCUGUUGCAUUGC  44 hsa-miR-3200-3p CACCUUGCGCUACUCAGGUCUG  45 hsa-miR-548o-5p AAAAGUAAUUGCGGUUUUUGCC  46 hsa-miR-152 UCAGUGCAUGACAGAACUUGG  47 hsa-miR-548am- AAAAGUAAUUGCGGUUUUUGCC 5p  48 hsa-miR-548au- AAAAGUAAUUGCGGUUUUUGC 5p  49 hsa-miR-548c-5p AAAAGUAAUUGCGGUUUUUGCC  50 brain-mir-248S GGCGGCGGAGGCGGCGGUG  51 hsa-miR-215 AUGACCUAUGAAUUGACAGAC  52 hsa-miR-340-5p UUAUAAAGCAAUGAGACUGAUU  53 hsa-miR-1301 UUGCAGCUGCCUGGGAGUGACUUC  54 brain-mir-145 AAGCACUGCCUUUGAACCUGA  55 hsa-miR-504 AGACCCUGGUCUGCACUCUAUC  56 hsa-miR-30d-5p UGUAAACAUCCCCGACUGGAAG  57 hsa-miR-4781-3p AAUGUUGGAAUCCUCGCUAGAG  58 hsa-miR-151a-3p CUAGACUGAAGCUCCUUGAGG  59 brain-mir-112 AGCUCUGUCUGUGUCUCUAGG  60 hsa-miR-28-3p CACUAGAUUGUGAGCUCCUGGA  61 hsa-miR-26b-3p CCUGUUCUCCAUUACUUGGCUC  62 hsa-miR-1468 CUCCGUUUGCCUGUUUCGCUG  63 hsa-miR-128 UCACAGUGAACCGGUCUCUUU  64 hsa-miR-550a-5p AGUGCCUGAGGGAGUAAGAGCCC  65 hsa-miR-5010-3p UUUUGUGUCUCCCAUUCCCCAG  66 hsa-miR-148b-5p AAGUUCUGUUAUACACUCAGGC  67 brain-mir-395 CACUGCACUCCAGCCUGGGUGA  68 brain-mir-308 CACUGCACUCCAGCCUGGGUGA  69 hsa-miR-1285-5p GAUCUCACUUUGUUGCCCAGG  70 hsa-miR-5001-3p UUCUGCCUCUGUCCAGGUCCUU  71 hsa-miR-3127-3p UCCCCUUCUGCAGGCCUGCUGG  72 hsa-miR-3157-3p CUGCCCUAGUCUAGCUGAAGCU  73 brain-mir-431 CUCGGCCUUUGCUCGCAGCACU  74 hsa-miR-550a-3- AGUGCCUGAGGGAGUAAGAG   5p  75 hsa-miR-361-5p UUAUCAGAAUCUCCAGGGGUAC  76 brain-mir-83 CAGGGUCUCGUUCUGUUGCC  77 hsa-miR-589-5p UGAGAACCACGUCUGCUCUGAG  78 hsa-miR-425-5p AAUGACACGAUCACUCCCGUUGA  79 hsa-miR-30a-5p UGUAAACAUCCUCGACUGGAAG  80 brain-mir-79 CACUGCACUCCAGCCUGGCU  81 brain-mir-80 CACUGCACUCCAGCCUGGCU  82 hsa-miR-330-5p UCUCUGGGCCUGUGUCUUAGGC  83 hsa-miR-186-5p CAAAGAAUUCUCCUUUUGGGCU  84 brain-mir-390 ACUGCAACCUCCACCUCCUGGGU  85 hsa-let-7d-3p CUAUACGACCUGCUGCCUUUCU  86 hsa-miR-328 CUGGCCCUCUCUGCCCUUCCGU  87 hsa-miR-30c-5p UGUAAACAUCCUACACUCUCAGC  88 brain-mir-200 UUCCUGGCUCUCUGUUGCACA  89 hsa-miR-363-3p AAUUGCACGGUAUCCAUCUGUA  90 hsa-miR-339-3p UGAGCGCCUCGACGACAGAGCCG  91 brain-mir-114 CACUGCAACCUCUGCCUCCGGU  92 hsa-miR-942 UCUUCUCUGUUUUGGCCAUGUG  93 hsa-miR-345-5p GCUGACUCCUAGUCCAGGGCUC  94 brain-mir-247 ACGCCCACUGCUUCACUUGACUAG  95 hsa-miR-4742-3p UCUGUAUUCUCCUUUGCCUGCAG  96 brain-mir-314 ACUCCCACUGCUUCACUUGAUUAG  97 brain-mir-12 ACUCCCACUGCUUGACUUGACUAG  98 brain-mir-232 UUGCUCUGCUCUCCCUUGUACU  99 brain-mir-424S CACUGCACUCCAGCCUGGGUA 100 brain-mir-219 UCAAGUGUCAUCUGUCCCUAGG 101 hsa-miR-10a-5p UACCCUGUAGAUCCGAAUUUGUG 102 hsa-miR-3605-3p CCUCCGUGUUACCUGUCCUCUAG 103 brain-mir-52 CUGCACUCCAGCCUGGGCGAC 104 brain-mir-53 CCCAGGACAGUUUCAGUGAUG 105 hsa-miR-3157-5p UUCAGCCAGGCUAGUGCAGUCU 106 brain-mir-41S CCCCGCGCAGGUUCGAAUCCUG 107 brain-mir-201 CACCCCACCAGUGCAGGCUG 108 hsa-miR-5006-3p UUUCCCUUUCCAUCCUGGCAG 109 hsa-miR-4659a- UUUCUUCUUAGACAUGGCAACG 3p 110 brain-mir-279 AUCCCACCGCUGCCACAC 111 brain-mir-111 CACUGCUAAAUUUGGCUGGCUU 112 brain-mir-88 UCUUCACCUGCCUCUGCCUGCA 113 brain-mir-251 UGGCCCAAGACCUCAGACC 114 hsa-miR-4435 AUGGCCAGAGCUCACACAGAGG 115 hsa-miR-5690 UCAGCUACUACCUCUAUUAGG 116 brain-mir-166 CUGGCUGCUUCCCUUGGUCU 117 brain-mir-193 AUCCCUUUAUCUGUCCUCUAGG 118 hsa-miR-625-5p AGGGGGAAAGUUCUAUAGUCC 119 hsa-miR-10b-5p UACCCUGUAGAACCGAAUUUGUG 120 brain-mir-299 CAUGCCACUGCACUCCAGCCU 121 brain-mir-153 CCUCUUCUCAGAACACUUCCUGG 122 hsa-miR-758 UUUGUGACCUGGUCCACUAACC 123 hsa-miR-30a-3p CUUUCAGUCGGAUGUUUGCAGC 124 brain-mir-220 UCCGGAUCCGGCUCCGCGCCU 125 brain-mir-392 CCCGCCUGUCUCUCUCUUGCA 126 brain-mir-102 UAUGGAGGUCUCUGUCUGGCU 127 hsa-let-7b-3p CUAUACAACCUACUGCCUUCCC 128 hsa-miR-340-3p UCCGUCUCAGUUACUUUAUAGC 129 hsa-miR-484 UCAGGCUCAGUCCCCUCCCGAU 130 hsa-miR-30e-3p CUUUCAGUCGGAUGUUUACAGC 131 brain-mir-72S GACCACACUCCAUCCUGGGC 132 hsa-miR-371b-5p ACUCAAAAGAUGGCGGCACUUU 133 hsa-miR-5581-3p UUCCAUGCCUCCUAGAAGUUCC 134 brain-mir-399 CACUGCAACCUCUGCCUCC 135 brain-mir-403 AAAGACUUCCUUCUCUCGCCU 136 brain-mir-73 UCCGGAUGUGCUGACCCCUGCG 137 brain-mir-190 CCUGACCCCCAUGUCGCCUCUGU 138 brain-mir-188 CCUGACCCCCAUGUCGCCUCUGU 139 brain-mir-189 CCUGACCCCCAUGUCGCCUCUGU 140 brain-mir-192 CCUGACCCCCAUGUCGCCUCUGU 141 brain-mir-311 CACUGCAACCUCUGCCUCCCGA 142 brain-mir-161 CUUCGAAAGCGGCUUCGGCU 143 hsa-miR-3074-5p GUUCCUGCUGAACUGAGCCAG 144 hsa-miR-30b-5p UGUAAACAUCCUACACUCAGCU 145 hsa-miR-576-5p AUUCUAAUUUCUCCACGUCUUU 146 brain-mir-23 UUAGUGGCUCCCUCUGCCUGCA 147 hsa-miR-943 CUGACUGUUGCCGUCCUCCAG 148 brain-mir-351 UGUCUUGCUCUGUUGCCCAGGU 149 hsa-miR-4772-3p CCUGCAACUUUGCCUGAUCAGA 150 brain-mir-319 CUGCACUCCAGCCUGGGCGA 151 hsa-miR-937 AUCCGCGCUCUGACUCUCUGCC 152 hsa-miR-181a-2- ACCACUGACCGUUGACUGUACC 3p 153 hsa-miR-4755-5p UUUCCCUUCAGAGCCUGGCUUU 154 hsa-miR-3909 UGUCCUCUAGGGCCUGCAGUCU 155 hsa-miR-1260b AUCCCACCACUGCCACCAU 156 brain-mir-293 UUGGUGAGGACCCCAAGCUCGG 157 brain-mir-160 CACUGCAACCUCUGCCUCC 158 hsa-miR-2110 UUGGGGAAACGGCCGCUGAGUG 159 hsa-miR-584-3p UCAGUUCCAGGCCAACCAGGCU 160 brain-mir-129 CAUGGUCCAUUUUGCUCUGCU 161 hsa-miR-1280 UCCCACCGCUGCCACCC 162 hsa-miR-3180-5p CUUCCAGACGCUCCGCCCCACGUCG 163 hsa-miR-668 UGUCACUCGGCUCGGCCCACUAC 164 hsa-miR-4512 CAGGGCCUCACUGUAUCGCCCA 165 hsa-miR-641 AAAGACAUAGGAUAGAGUCACCUC 166 hsa-miR-1233 UGAGCCCUGUCCUCCCGCAG 167 hsa-miR-378a-5p CUCCUGACUCCAGGUCCUGUGU 168 hsa-miR-26a-5p UUCAAGUAAUCCAGGAUAGGCU 169 brain-mir-258 AUCCCACCCCUGCCCCCA 170 hsa-miR-1260a AUCCCACCUCUGCCACCA 171 hsa-miR-29c-3p UAGCACCAUUUGAAAUCGGUUA 172 hsa-miR-29a-3p UAGCACCAUCUGAAAUCGGUUA 173 hsa-let-7e-5p UGAGGUAGGAGGUUGUAUAGUU 174 hsa-let-7a-5p UGAGGUAGUAGGUUGUAUAGUU 175 hsa-let-7f-5p UGAGGUAGUAGAUUGUAUAGUU 176 hsa-miR-29b-3p UAGCACCAUUUGAAAUCAGUGUU 177 hsa-miR-98 UGAGGUAGUAAGUUGUAUUGUU 178 hsa-miR-425-5p AAUGACACGAUCACUCCCGUUGA 179 hsa-miR-223-3p UGUCAGUUUGUCAAAUACCCCA 180 hsa-miR-181a-2- ACCACUGACCGUUGACUGUACC 3p 181 hsa-miR-148b-3p UCAGUGCAUCACAGAACUUUGU 182 brain-mir-145 AAGCACUGCCUUUGAACCUGA 183 hsa-miR-548h-5p AAAAGUAAUCGCGGUUUUUGUC 184 hsa-miR-550a-5p AGUGCCUGAGGGAGUAAGAGCCC 185 hsa-miR-374b-5p AUAUAAUACAACCUGCUAAGUG 186 hsa-miR-339-3p UGAGCGCCUCGACGACAGAGCCG 187 hsa-miR-3661 UGACCUGGGACUCGGACAGCUG 188 brain-mir-190 CCUGACCCCCAUGUCGCCUCUGU 189 brain-mir-188 CCUGACCCCCAUGUCGCCUCUGU 190 brain-mir-189 CCUGACCCCCAUGUCGCCUCUGU 191 brain-mir-192 CCUGACCCCCAUGUCGCCUCUGU 192 hsa-miR-550a-3- AGUGCCUGAGGGAGUAAGAG 5p 193 hsa-miR-199a-3p ACAGUAGUCUGCACAUUGGUUA 194 hsa-miR-199b-3p ACAGUAGUCUGCACAUUGGUUA 195 hsa-miR-660-5p UACCCAUUGCAUAUCGGAGUUG 196 hsa-miR-190a UGAUAUGUUUGAUAUAUUAGGU 197 brain-mir-220 UCCGGAUCCGGCUCCGCGCCU 198 hsa-miR-548g-5p UGCAAAAGUAAUUGCAGUUUUUG 199 hsa-miR-548ar- AAAAGUAAUUGCAGUUUUUGC 5p 200 hsa-miR-548x-5p UGCAAAAGUAAUUGCAGUUUUUG 201 hsa-miR-548aj- UGCAAAAGUAAUUGCAGUUUUUG 5p 202 brain-mir-394 AAAAGUAAUCGUAGUUUUUG 203 brain-mir-149 AAAAGUAAUCGCACUUUUUG 204 brain-mir-151 AAAAGUAAUCGCACUUUUUG 205 hsa-let-7c UGAGGUAGUAGGUUGUAUGGUU 206 brain-mir-333 AAAAGUAAUCGCAGGUUUUG 207 brain-mir-170 AAAAGUAAUGGCAGUUUUUG 208 hsa-miR-152 UCAGUGCAUGACAGAACUUGG 209 hsa-miR-15a-5p UAGCAGCACAUAAUGGUUUGUG 210 hsa-miR-197-5p CGGGUAGAGAGGGCAGUGGGAGG 211 brain-mir-399 CACUGCAACCUCUGCCUCC 212 hsa-miR-3158-3p AAGGGCUUCCUCUCUGCAGGAC 213 brain-mir-150 UGAGGUAGUAGGUGGUGUGC 214 hsa-miR-424-3p CAAAACGUGAGGCGCUGCUAU 215 hsa-miR-148a-3p UCAGUGCACUACAGAACUUUGU 216 hsa-miR-3200-3p CACCUUGCGCUACUCAGGUCUG 217 hsa-miR-628-3p UCUAGUAAGAGUGGCAGUCGA 218 hsa-let-7d-5p AGAGGUAGUAGGUUGCAUAGUU 219 hsa-miR-4781-3p AAUGUUGGAAUCCUCGCUAGAG 220 brain-mir-160 CACUGCAACCUCUGCCUCC 221 hsa-miR-374a-5p UUAUAAUACAACCUGAUAAGUG 222 hsa-miR-338-3p UCCAGCAUCAGUGAUUUUGUUG 223 hsa-miR-340-5p UUAUAAAGCAAUGAGACUGAUU 224 brain-mir-395 CACUGCACUCCAGCCUGGGUGA 225 brain-mir-308 CACUGCACUCCAGCCUGGGUGA 226 brain-mir-53 CCCAGGACAGUUUCAGUGAUG 227 brain-mir-229 AUCCCACCUCUGCUACCA 228 hsa-miR-151a-3p CUAGACUGAAGCUCCUUGAGG 229 hsa-miR-1234 UCGGCCUGACCACCCACCCCAC 230 hsa-miR-874 CUGCCCUGGCCCGAGGGACCGA 231 hsa-miR-548av- AAAAGUACUUGCGGAUUU 5p 232 hsa-miR-548k AAAAGUACUUGCGGAUUUUGCU 233 brain-mir-101 AGACCUACUUAUCUACCAACA 234 hsa-miR-30d-5p UGUAAACAUCCCCGACUGGAAG 235 hsa-miR-3200-5p AAUCUGAGAAGGCGCACAAGGU 

What is claimed is:
 1. A method of analyzing miRNA in a blood sample taken from a patient, said method comprising the step of: a) determining in said blood sample expression level of: miRNA having the nucleotide sequence of SEQ ID NO: 142 and miRNA having the nucleotide sequence of SEQ ID NO:
 59. 2. The method according to claim 1, further comprising determining expression level miRNA having the nucleotide sequence of SEQ ID NO:
 69. 3. The method according to claim 2, comprising determining expression level of: miRNA having the nucleotide sequence of SEQ ID NO: 69, miRNA having the nucleotide sequence of SEQ ID NO: 142, miRNA having the nucleotide sequence of SEQ ID NO: 2, miRNA having the nucleotide sequence of SEQ ID NO: 59, miRNA having the nucleotide sequence of SEQ ID NO: 58, and miRNA having the nucleotide sequence of SEQ ID NO:
 65. 4. The method according to claim 1, wherein the determination of the expression level in step (a) is obtained by use of a method selected from the group consisting of a Sequencing-based method, an array based method and a polymerase chain reaction (PCR) based method.
 5. The method according to claim 1, comprising determining expression levels of at least 2, 3, 4, 5, or 6 miRNAs.
 6. The method according to claim 1, wherein the patient is a healthy subject.
 7. The method according to claim 1, wherein the patient is suffering from or at risk of developing Parkinson's Disease (PD) or a neurological disease other than PD.
 8. The method according to claim 7, wherein the other neurological disease is selected from the group consisting of Alzheimer's disease (AD), Cognitive Impairment (MCI), Multiple Sclerosis (MS), Mild Depression, Bipolar Disorder (BD), and Schizophrenia.
 9. The method of claim 1, wherein the blood sample is a blood cell sample.
 10. The method of claim 7, wherein the patient has early symptoms of Parkinson's Disease (PD) or a neurological disease other than PD.
 11. The method according to claim 4, wherein the determination of the expression level in step (a) is obtained by next-generation sequencing (NGS) or quantitative reverse transcription PCR (qRT-PCR).
 12. The method according to claim 1, further comprising determining expression level of miRNA having the nucleotide sequence of SEQ ID NO:
 2. 13. The method according to claim 1, further comprising determining expression level of miRNA having the nucleotide sequence of SEQ ID NO:
 58. 14. The method according to claim 1, further comprising determining expression level of miRNA having the nucleotide sequence of SEQ ID NO:
 65. 